Method and heat-exchanger for preheating broken glass and glass-batching melt-goods or similar bulk goods using a heating gas

Abstract

As a rule a melt-good consisting of glass fragments and glass batching will be moist and tend to agglomerate and bridge-form when being preheated in a plate heat-exchanger 10 whereby the travel of the melt-good through the plate heat-exchanger 10 may be blocked. To remedy these drawbacks, the preheating stage is preceded by a drying stage of the moist melt-good. For that purpose, in the intake zone of the melt-good, the moisture of the melt-good is evaporated by means of a separate feed of hot heating gas into the already cooled flows of heating gas. At the same time the heated melt-good is made to pass through cavities 12 through which the steam may escape to the outside. Thereby condensation shall be precluded and only fluid or friable melt-good arrives at the preheating stage.

We claim: 
     
       1. In a plate heat-exchanger to preheat melt goods using a heating gas comprising a melt good preheating zone including a plurality of mutually spaced small vertical ducts open at a top and bottom thereof to transmit the melt-goods by gravity, cavities between walls of the ducts receiving the heating gas, the heating gas entering through a lower feed conduit and exiting through an upper evacuation conduit, the improvement comprising, (a) when viewed from the top toward the bottom, the plate heat-exchanger (10) further comprises a drying zone adjoined to a top of the melt-good preheating zone,   (b) the drying zone comprising means (24, 27, 28, 20) for feeding the heating gas into the cavities (20a) and further means (12, 29, 31) with additional cavities (29a) for evacuating steam generated by drying the melt-goods, the further means mounted in the plate heat-exchanger (10) transversely to a direction of motion of the melt-goods to evacuate the steam from one end of the plate heat-exchanger (10).     
     
     
       2. Plate heat-exchanger defined in claim 1, wherein the drying zone starts at a depth of approximately 1-2 m from a top of the plate heat-exchanger. 
     
     
       3. Plate heat-exchanger defined in claim 1, wherein the means (28, 20) for feeding the heating gas and the means (12, 29, 29a, 31) for evacuating the steam from the drying zone are directly vertically adjacent each other. 
     
     
       4. Plate heat-exchanger defined in claim 1, wherein the means (12, 31) for evacuating the steam from the drying zone comprises bodies (29) having at least one opening on underside thereof, said at least one opening receiving steam for evacuation. 
     
     
       5. Plate heat-exchanger defined in claim 4, wherein the bodies (29) for the evacuation of steam from the drying zone are mounted in one or more vertically spaced planes in the drying zone. 
     
     
       6. Plate heat-exchanger defined in claim 1, wherein said plate heat-exchanger further comprises a plurality of individual heat-exchanger units (11) designed to be horizontally crossed by the heating gas and wherein the cavities (20a) of adjacent heat-exchanger units (11) are connected by externally mounted heating-gas bypass-ducts (25), the bodies (29) for evacuating the steam being integrated into at least one intermediate unit (12) mounted between two adjacent heat-exchanger units (11), said cavities in uppermost heat-exchanger units connected to a preheating zone bypass duct (27, 28).   
     
     
       7. Plate heat-exchanger defined in claim 6, wherein the bodies (29) are integrated into the at least one intermediate unit (12) so that they are each located between aligned cavities (20a) of the adjacent heat-exchanger units (11). 
     
     
       8. Plate heat-exchanger defined in claim 7, wherein the bodies (29) further comprise one of reversely mounted U-channels, V-sections, and H-shaped bars. 
     
     
       9. Plate heat-exchanger defined in claim 8, wherein the bodies (29) are H-shaped and a cross-sectional width of each of the H-shaped bars (29) corresponds to a cross-sectional width of a cavity (20a) vertically adjoined to the H-shaped bars (29). 
     
     
       10. Plate heat-exchanger defined in claim 9, wherein angle-irons (34) are integrated in a prone manner into the at least one intermediate unit (12), said angle-irons (34) vertically spaced from, parallel to the H-shaped bars (29), and vertically flush with the H-shaped bars (29), legs of the angle-irons (34) forming deflecting surfaces for the melt-goods flowing through at least one intermediate unit 12.